Image converters are employed in many areas. For example, since the human eye is not sensitive to electromagnetic radiation in the infrared region, a converter may be used to detect infrared radiation. The detected infrared scene may be displayed on a spatial light modulator (SLM). Converter systems may also be used for image projection. Once the image is displayed on the SLM, the user can view it on the SLM or project the image on a screen. The nature of this projected image is the product of the original image and the projecting light beam. Finally, a converter system may be used for optical signal processing.
Known converters generally include light sensing devices, such as a camera, an SLM, and a beam splitter. The camera captures the image of an object or scene. The SLM displays the image and spatially modulates the beam either in transmission or in reflection. The beam splitter, when employed, may split and combine the beams on which the image displayed by the SLM is superimposed. See, for example, U.S. Pat. No. 4,462,046. However, since known converters accomplish conversion in the optical domain they have little or no flexibility for specific applications. In addition, previous systems have not allowed low distortion preprocessing or conditioning of the video signal before conversion to a coherent signal.